Dental hand tools often require fluids to operate. In particular, water can be used to cool a dental tool, as well as to irrigate a patient's mouth. Water can be supplied to the dental tool via a flexible conduit, such as a tube, that is connected to the hand tool at one end, and an instrument console at another end. Due to the nature of the work being performed in the patient's mouth, any water that enters the patient's mouth must be free from pathogens that might cause an infection. Accordingly, the U.S. Center for Disease Control (“CDC”) recommends that the number of bacteria in water used as a coolant/irrigant for nonsurgical dental procedures should have an aerobic heterotropic plate count (“HPC”) of ≦500 colony forming units (“CFU”)/ml. This number was selected based on a recommendation for levels of HPC in potable water. In addressing this issue, the American Dental Association (“ADA”) has proposed that water used in dental treatment contain a bacterial level of ≦200 CFU/ml. E. W. Rice, W. K. Rich, C. H. Johnson, and D. J. Lye, “The Role of Flushing Dental Water Lines for the Removal of Microbial Contaminants”, Public Health Rep. May-June 2006; 121(3): 270-274. HPC counts as high as ˜30,000 CFU/ml have been detected for dental supply systems with no disinfection precautions, and other precautions such as flushing of the lines still results in HPC counts above the recommended values. Pathogens such as Pseudomonas, Klebsiella, Legionella, and non-tuberculosis Mycobacterium species have been detected in water from dental supply lines. H. S. Bednarsh, K. J. Eklund, and S. Mills, “Dental Unit Waterlines: Check Your Dental Water Unit IQ”, Access Vol. 10, No. 9, copyright ©1997 by the American Dental Hygienists' Association. Pseudomonas is a well-known opportunistic pathogen and a common contaminant in dental unit water.
Several techniques for treating dental fluids have been developed because of the pathogens that have been found in the dental fluids. One method includes installing a UV disinfection unit in the instrument console, to treat the fluid in the console. Chemical treatment of the supply lines, for example chlorine or ozone, has been used. Microbial filters have also been installed at the dental hand tool to treat the dental fluid as it enters the hand tool.